Novel Micro-Implant to Measure Intracardiac Pressure in Congenital Heart Patients

描述（申请人提供）：具有功能性单心室（FSV）解剖结构的先天性心脏病患者通常需要在婴儿期和儿童期进行一系列手术，以使他们有机会存活到成年。第二阶段手术，称为半fontan手术（HFP），将全身静脉血从上半身和头部重新输送到肺循环，而不经过中间的心室。由于血液流入肺部在很大程度上是一个被动过程，任何肺血管内的解剖性阻塞、肺血管阻力升高或显著的心室功能障碍都可导致患者半fontan压升高。在分阶段姑息过程早期在半Fontan通路内出现的问题可导致Fontan手术期间和Fontan患者一生中并发症的风险增加。因此，维持最佳的半丰坦解剖和生理对FSV患者的长期成功和生存至关重要。目前，在大多数机构中，在手术后立即或在等待Fontan的门诊环境中常规测量半Fontan通路压力并不是标准做法。术后监测半丰坦压需要在上肢或颈部静脉留置导管。这有可能导致全身静脉完全血栓形成，这对半fontan患者来说是一个毁灭性的并发症。此外，连续门诊心导管测量半丰坦压力会使婴儿面临手术并发症的风险。因此，为了给ICU和门诊的临床医生提供测量半fontan压力的方法，研究人员正在开发一种小型化的压力传感器，可以在第二阶段手术时直接植入半fontan通路。拟议的植入式压力监测仪将在术后立即提供半Fontan通路的血流动力学评估，而不会有全身静脉血栓形成的风险。在门诊环境中对半fontan通路压力进行间歇测试，将使临床医生能够观察到压力上升的趋势，这可能为正在发展的问题提供早期指示，并允许在不可逆损伤发生之前进行早期干预。这将在没有心导管相关风险的情况下完成。在这项研究中，研究人员将完成微型植入式无线压力传感器的开发。最终设计冻结将实现，设计控制要求，包括风险分析、生物相容性测试、无菌性和制造工艺，将完成，以满足FDA的要求。将进行临床前动物研究，包括慢性GLP动物研究，以确定该设备的体内生物相容性、功能和安全性。最后，本研究将支持研究人员在申请过程中获得FDA的研究器械豁免，用于对患有这些复杂形式先天性心脏病的婴儿进行初步可行性研究。

DESCRIPTION (provided by applicant): Congenital heart disease patients with functional single ventricle (FSV) anatomy usually require a series of surgeries during infancy and childhood in order to provide them with a chance to survive into adulthood. The second stage surgery, termed the hemi-Fontan procedure (HFP) re-routes systemic venous blood from the upper body and head into the pulmonary circulation without passing through an intervening ventricular chamber. Because blood flow into the lungs is largely a passive process, any anatomic obstruction within the pulmonary vasculature, elevated pulmonary vascular resistance, or significant ventricular dysfunction can result in patients having elevated hemi-Fontan pressures. Problems that develop within the hemi-Fontan pathway early in the staged palliation process can result in an increased risk for complications during the Fontan operation and throughout a Fontan patient's life. Therefore, maintaining optimal hemi-Fontan anatomy and physiology is important for long term success and survival for FSV patients. Currently, it is not standard practice at most institutions to routinely measure hemi-Fontan pathway pressures in the immediate post- operative period or in the ambulatory setting while awaiting the Fontan. Post-operative monitoring of the hemi- Fontan pressures requires an indwelling catheter in an upper body or neck vein. This has the potential to lead to complete thrombosis of the systemic vein, which is a devastating complication for the hemi-Fontan patient. Furthermore, serial outpatient cardiac catheterizations to measure hemi-Fontan pressures place infants at risk for procedural complications. Therefore, to provide clinicians in the ICU and in the ambulatory setting with the means to measure hemi-Fontan pressures, investigators are developing a miniaturized pressure sensor that can be implanted directly into the hemi-Fontan pathway at the time of the second stage operation. The proposed implantable pressure monitor will provide readily available hemodynamic assessment of the hemi- Fontan pathway during the immediate post-operative period without the risk of systemic venous thrombosis. Interval testing of the hemi-Fontan pathway pressure in the ambulatory setting will allow clinicians to observe for rising pressure trends, which may provide early indication of a problem that is developing and allow for earlier intervention before irreversible damage has occurred. This will be accomplished without the risk associated with cardiac catheterization. During this study investigators will complete the development of a miniature implantable wireless pressure sensor. Final design freeze will be achieved, and design control requirements, including risk analysis, biocompatibility testing, sterility, and manufacturing processes, will be completed to satisfy FDA requirements. Preclinical animal studies will be carried out, including a chronic GLP animal study, to determine the device's in vivo biocompatibility, functionality, and safety profile. Finally, this study will support investigators during the application process to obtain Investigational Device Exemption from the FDA for the initial feasibility studies in infants with these complex forms of congenital heart disease.